DE1022957B - Process for producing a flat, electrically conductive connection between a metallic and a ceramic workpiece - Google Patents

Description

GERMAN

The invention relates to a method for the electrically conductive surface connection of two bodies, of one made of metal and the other made of ceramic material, with each other.

So far, in practice, electrically conductive connections of such bodies were mostly in a multi-stage manner Manufactured by first coating the ceramic body or object with silver and then through a following baking treatment a silver-plated surface is formed on which the metal body with the ceramic Body is welded using either a tin-lead alloy or a silver alloy. It is also already known to use a so-called sintered metal cement to ceramic bodies with a metal body to connect and the layer of this sintered metal with an outer protective layer Cover glass.

Furthermore, it has already been proposed to use an electrically conductive metal body and ceramic body To connect the intermediate layer, which consists of an adhesive, flux-containing metal preparation, for. B. off pure silver, silver salts or organic silver compounds, and one that solidifies glassy from the melt Flux dispersed in a suitable vehicle, such as a solution of a resin in oil, consists.

All of these known methods are complicated and do not give a reliable, tight connection from the same time perfect electrical conductivity and the latter especially because they do not allow to increase the conductive metal content of the intermediate layer to the level necessary for this purpose.

According to the invention, a flat, electrically conductive connection between a metallic and a ceramic workpiece produced in that one essentially of silver and in a finely divided state In a suitable carrier suspended in a glass existing intermediate layer introduced between the body and is burned together with them.

The use of a real glass as a means of embedding the silver particles makes it possible to keep it safe a conceivably favorable adhesion of the intermediate layer to the bodies to be connected, their content to reduce considerably on glass, in other words, the silver content considerably, on the order of magnitude up to 95%, to increase.

The connection produced according to the invention between the ceramic and the metal body is opposite high temperatures of the order of 425 ° C and more, at which the majority of soft solders melt, resilient and also has better electrical conductivity than that using connections made by soft solders. As a result, there is better electrical contact

Method for producing a flat, electrically conductive connection of a metallic with a ceramic

workpiece

Applicant:

Gulton Mfg. Corp.,

Metuchen, N.J. (V.St.A.)

Representative: Dipl.-Ing. RH Bahr, patent attorney,
Herne (Westphalia), Schaeferstr. 60

Claimed priority:
V. St. v. America from November 26, 1952 ¹

James M. Brownlow, Beacon, NY (V. St. Α.),
has been named as the inventor

between the ceramic and the metal body, the vacuum body formed from these with synthetic resins covered by high deformation temperatures or glazed enamels with a high melting point or in such synthetic resins or enamels can be immersed. The metal-ceramic composite body produced using the new process Because of its special features mentioned, it is particularly suitable for manufacture of capacitors with ceramic dielectric for high frequency and analog equipment.

Further features and details of the invention will become apparent in the following description thereof the illustrations are explained. From the pictures shows

Fig. 1 in section a metal and a ceramic body in side-by-side arrangement, which by a the ceramic body applied layer are to be connected;

Fig. 2 is a section similar to Fig. 1 of the two bodies in the cemented together state;

Fig. 3 shows on a larger scale a detail of the arrangement shown in Fig. 1;

FIG. 4 is a representation analogous to FIG. 3, which shows the metal and ceramic bodies in one with one another Shows conditions before heating, and

Fig. 5 is a view similar to Figs. 3 and 4 showing the two bodies finally firmly joined together illustrated.

709 849/365

3 4

Destroyed by the body by the method according to the invention and replaced by molten glass bodies to be connected with one another is in the process of being. Now the whole is cooled, so that then Formations of the ceramic body with 10 and the metal the connecting layer a rigid glass layer 16 in which body. marked 11. The two bodies will form the finely divided silver 14 is dispersed. By connected to each other by the connecting layer 12. 5 this strengthening of the glass of the intermediate layer 16 The metal as well as the ceramic body 10 and 11 are the ceramic body 10 and the metal bodies can have any desired shape. Connected to each other for the purpose of solidarity, whereby because of the simplification of the description, they are finely dispersed in the binding layer in the figures as plates or elements formed in an analogous manner therewith, the intermediate layer is electrically contained in the silver 14 been asked. io is conductive.

The ceramic body 10 can be made of ceramic materials. Below are some typical examples of materials from very different compositions of the ceramic and the metal composition, among which, as examples, the dielectrics on the body and the connecting layer, which are particularly titanate, steatite, porcelain and the other densities have proven suitable: ceramic materials as well as glass may be mentioned exist. 15th
The composition of the metal body 11 should be

be such that it can withstand temperatures between 540 ceramic bodies and is resistant to 870 ° C without oxidizing or corroding. He can therefore z. B. made of silver, silver-plated The following offsets are particularly suitable for Her-Kupfer, silver-plated brass, silver alloys, ferro- 20 position of multicrystalline moldings according to the Nickel, nickel-manganese or iron-chromium-nickel alloy common ceramic working methods: struggle.

The connecting layer 12, which is the adhesion between offset 1. TiO ₂ 88 percent by weight

the ceramic body 10 and the metal body 11 Zr 0 »5 ,,

causes, can be used in the form of a paint, 25 MgTiO ₃ 5 "

which on the body by means of a brush, by on-tone 2 ,,

spray with a spray gun or by immersion _T , * 1 r>τ> · / -ν oo

^r *, j, ι-. j · Tr -L- j,. ,. Offset number BaIiO., 00 "

can be applied. The connecting layer E 7 O 8

forming substance contains, as indicated in Fig. 3 and 4, M 7 O 4 '

finely divided glass 13 which, when the coating is heated, 30 se >>

to a temperature between 540 and 870 ⁰ C either offset 3. steatite, consisting of

sinters or melts. It also contains silver in fine talc 85 percent by weight

distributed state, indicated by 14 in FIGS. 1 to 5. Tone 5 ,,

This silver can either be in colloidal form or in BaCO ₃ 10

Form of an organic silver salt like 35
are in the form of a mixture of colloidal silver and silver salts. The glass 13 and the silver 14 are metals in suspension in a carrier 15 which, for. B. from one

organic resinous substance, such as a lacquer or a 1st wire made of a nickel-iron alloy with 95%

analogous substance, or from a synthetic resin, 40 nickel and 5% iron.

such as vinyl resins, cellulose acetate, methyl methacrylate, 2. Silver-plated copper sheets; Copper tape made of 125 ml-butyl methyl acrylate or analogous substances. The resinous support 15 preferably contains a silver deposit of 12 to 25 microns thick, a suitable solvent for the resin in question, in order to make the coating possible or the connection 45 an electrolytically produced silver layer on the ceramic and the metal body 10 is deposited from 12 to 25 microns thick, or 11 like an ordinary paint, ie with the
Brush, spray gun or dipping, can be applied. Link layer

As can be seen from FIG. 3, the glass 13, the 50 _{7 1}

Silver 14 and the carrier 15 as well as the solvent for composition 1:

this containing compound layer on the ceramic- finely divided metallic silver 95%

see body 10 applied. Then the metal-glass powder is made of the following composition: body 11 applied to the ceramic body so that

through the intermediate connecting layer 12 a 55 Pb O 26% "1

coherent composite body is formed, the B ₀ O ₃ 10% I _{ςο /}

is now first preheated to the solution Na ₂ O 3% f '°

drive agent from the tie layer. In Fig. 4 SiO ₀ 61% j

the overall arrangement is shown in this state. "". "" ".

The finely divided glass 13 and the equally finely divided 60 £ eststotte: iuu / ₀ silver 14 are now, even after the

Stripping the solvent from carrier 15, in carrier: toluene 70%

Suspension in this. Ethyl cellulose 20%

Now the whole is brought to a temperature of pine rosin 1 °%

heated between 540 and 870 ° C in order to melt the finely divided liquid substances: 100% glass 13 or at least to sinter it. in the
During this melting or sintering process, the glass particles 13 fuse with one another, and the solid and liquid substances are mixed with the layer is simultaneously mixed with the ceramic and the one another to form a paste or paint, cemented metal body, while the resin carrier- 70 which is ready for use as such.

Composition 2:
Like silver ....

95%

Bismuth oxide 0.5%

Glass powder of the following composition:

9%

37%

10 ¹ Vo

4%

40% J.

Solids:

Al ₂ O ₃
PbO
B ₂ O ₃
CaO.
SiO ₂ .

Glass 4,50 / e

100

Carrier: nitrocellulose 30%

Butyl acetate 10%

Monoethyl glycol ether 20%

Nitro benzine 40%

Liquid substances: 100%

These solids and the liquid components are combined to form a ready-to-use paste or mixed with one coat.

It goes without saying that the invention is in no way limited to the embodiments described in detail above and examples are limited, but are opposed to it

numerous changes are possible without deviating from its basic idea.

Claims (3)

PATENT CLAIMS: 1. Method for producing a flat, electrically conductive connection of a metallic with a ceramic workpiece through one essentially made of silver and one in finely divided State of the intermediate layer consisting of mineral flux suspended in a suitable carrier, which is fired together with the bodies to be joined, characterized in that a mineral flux is used, which consists of glass. 2. The method according to claim 1, characterized in that a connecting layer is used, whose silver content is in the order of 95%. 3. The method according to claim 1 and 2, characterized in that the firing is carried out at a temperature of 540-870 ⁰ C. Considered publications:
German Patent No. 867,975;
"Excerpts from German patent applications", Vol. 15, p. 613 (file number P 83 014 VIb). 1 sheet of drawings © 709 849/365 t. 58